What are the steps to manage ventricular tachycardia (V.TACH)?

Management of Ventricular Tachycardia (V.TACH)

The most effective and rapid means of terminating any hemodynamically unstable ventricular tachycardia is immediate DC cardioversion. 1

Initial Assessment and Stabilization

Hemodynamic Status Evaluation

• Assess for signs of hemodynamic instability:
  • Hypotension
  • Altered mental status
  • Chest pain
  • Heart failure
  • Shock

Management Based on Hemodynamic Status

Hemodynamically Unstable V.TACH

1. Immediate synchronized DC cardioversion (Class I recommendation)
   • Start with 100J (biphasic) or 200J (monophasic)
   • Increase energy as needed if initial shock fails
2. After cardioversion, initiate antiarrhythmic therapy to prevent recurrence:
   • Amiodarone IV: 150 mg over 10 minutes, followed by maintenance infusion of 1 mg/min for 6 hours, then 0.5 mg/min 2

Hemodynamically Stable V.TACH

1. Pharmacological therapy:

   • First-line: Procainamide IV 10 mg/kg at 50-100 mg/min (Class IIa recommendation) 3
     • Monitor blood pressure and ECG during administration
     • Maximum dose: 17 mg/kg
   • Alternative: Amiodarone IV 150 mg over 10 minutes, followed by 1 mg/min infusion for 6 hours, then 0.5 mg/min 2
   • Third option: Lidocaine IV 1-1.5 mg/kg bolus, followed by 0.5-0.75 mg/kg every 5-10 minutes (maximum 3 mg/kg)

2. If pharmacological therapy fails, proceed to synchronized cardioversion

Diagnostic Considerations

ECG Criteria for Diagnosing V.TACH

• QRS width >0.14 seconds with RBBB pattern or >0.16 seconds with LBBB pattern 1
• VA dissociation (pathognomonic but visible in only 30% of cases) 1
• Fusion beats (diagnostic of VT) 1
• RS interval >100 ms in any precordial lead (highly suggestive of VT) 1
• Negative concordance in precordial leads (diagnostic for VT) 1
• QR complexes (indicate myocardial scar, present in ~40% of post-MI VT) 1

Post-Acute Management

Short-term Management

• Continue antiarrhythmic therapy based on initial response:
  • Amiodarone: 0.5 mg/min infusion (720 mg/24 hours) for 2-3 weeks 2
  • Caution: Higher concentrations (>2 mg/mL) require central venous access 2
  • Monitor for hypotension, bradycardia, and QT prolongation

Long-term Management

1. ICD implantation is indicated for:

   • Documented syncopal ventricular tachycardia or fibrillation without correctable causes (Class I, Level A) 1
   • Patients with poor left ventricular function and VT 1

2. Catheter ablation:

   • Consider as first-line therapy in patients with ischemic cardiomyopathy and VT
   • Recent evidence shows catheter ablation leads to lower risk of composite endpoints compared to antiarrhythmic drug therapy alone 4

3. Chronic antiarrhythmic therapy:

   • Amiodarone is preferred for patients with structural heart disease or LV dysfunction
   • Beta-blockers for primary prevention of sudden cardiac death 5
   • Sotalol for patients without significant structural heart disease

Special Considerations

• Torsades de Pointes: Immediately discontinue any QT-prolonging drugs (Class I recommendation) 1
• Incessant VT: Consider sedation, mechanical ventilation, and hemodynamic support while preparing for definitive therapy
• VT Storm: Aggressive antiarrhythmic therapy with amiodarone plus beta-blockers, deep sedation, and urgent catheter ablation

Pitfalls and Caveats

• Do not delay cardioversion in hemodynamically unstable patients to administer medications
• Avoid administering calcium channel blockers (especially dihydropyridines) for VT as they may worsen hemodynamic status
• When using amiodarone IV, monitor closely for hypotension, especially with rapid infusion 2
• Amiodarone concentrations >3 mg/mL in D5W are associated with high incidence of peripheral vein phlebitis 2
• Do not use evacuated glass containers for admixing amiodarone due to potential precipitation 2